How to R&R Front driveshaft on a 72 3/4 ton 4x4? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**CPNE** · 03-02-2005, 11:56 AM

Stock height, original NP205, D44 FE. I need to remove the front driveshaft and replace it. I have a good donor. My question relates to how best to remove it. I've taken them out before, but always after removing the cab during a teardown. I know the u-joint bolts on the NP205 side are hard to get to even with unrestricted access. Who has pulled and replaced the front driveshaft from under the vehicle? I'd like a few pointers on how best to approach this task. Keep in mind, I'll be on my back under it, no lift here.

Thanks

BLAZERMAN · 03-02-2005, 12:33 PM

I allways start with the yoke at the transfer case first and use a prybar or large screwdriver through the front yoke to turn and hold the shaft in place. If your lucky you will have the 7/16" head bolts at the TC , just use the shortest wrench you have, if your exhuast is run through the crossmember it can get real tight. If you do have the 7/16" bolts you can use a ratcheting wrench but if you have the 1/2" head there wont be enough room.

**JIMs70GMC** · 03-02-2005, 07:36 PM

It's a pain even on lifted vehicles. My front output seal is leaking and in my situation I'm going to remove the crossmember. If you can remove the hump that would make it easier.

**Stocker** · 03-02-2005, 08:07 PM

Did mine recently on my back in the carport. Unbolted the front crossmember & moved it out of the way (only way I could get to the nuts at the TC end of the shaft). Then I just unbolted the rear of the shaft, then the front. Bit of a PITA, it just went slowly due to limited access.

jeffspower · 03-02-2005, 09:59 PM

Come on, guys. Not to brag, but it isn't that tough as long as the bolt heads are not chewed up from the last guy. If the bolt heads are buried in guuk, take a right angle pick & dig them out before you round them off. I use the lockouts to position it where I want it, and wrench the two bolts at the top. It takes a little arm twisting and dexterity. Once you get them broke loose with a long wrench, you can work them out quick with a stubby wrench. Reach over & spin a lockout to position it to get the other two bolts. Once you get the hang of it, you can R&R one in about 1/2 an hour.

**Stocker** · 03-03-2005, 09:58 AM

Well, mine had never been touched, so nothing was chewed up from the last guy. And I did not round anything off. But I could not see any way at all to reach anything with the crossmember in place, so I moved it (which is not difficult). For me, the easy access made it worthwhile. YMMV

4x4Poet · 03-04-2005, 05:00 AM

Jeffspower's advice is spot on. What makes it easier than it looks is the bolts screw into the yoke that takes the CV joint cross. They're little and fairly short. Initial bolt head cleanliness will greatly ease the task. IIRC, I used an offset box-end wrench in the backward position to make the handle angle away from the xfer case.

03-02-2005, 11:56 AM	#1
CPNE Resident Curmudgeon Join Date: Dec 1999 Location: NH Posts: 6,664	How to R&R Front driveshaft on a 72 3/4 ton 4x4? Stock height, original NP205, D44 FE. I need to remove the front driveshaft and replace it. I have a good donor. My question relates to how best to remove it. I've taken them out before, but always after removing the cab during a teardown. I know the u-joint bolts on the NP205 side are hard to get to even with unrestricted access. Who has pulled and replaced the front driveshaft from under the vehicle? I'd like a few pointers on how best to approach this task. Keep in mind, I'll be on my back under it, no lift here. Thanks __________________ Currently on or near the homestead: 67 Chevy SWB 2WD stepside 350/3 on tree (Pat's) 67 GMC SWB 2WD Fleet 402/auto (Brian's under construction) 67 Chevy 3/4 ton 2WD 402/auto (Business Hauler) 67 Chevy 1 ton dually 2WD 396/4 speed (Former business hauler, Needs TLC) 68 Chevy 1/2 ton Suburban 2WD 250 six/3 on tree (Brian's Needs TLC) 70 Chevy 3/4 ton 4WD 350/4 speed (Pat's - Disguised as a 68 GMC) 71 Chevy SWB stepside (Crushed by tree - parts donor) 72 Chevy 3/4 ton 4WD (Parts donor) 72 Chevy 3/4 ton 4WD Suburban (Parts Donor) 72 GMC 3/4 ton 4WD 292 six/4 speed (Mine - Disguised as a 67 GMC) 81 GMC 4WD Dually Dump Body 350/4 speed (Business Hauler) 82 Camaro Z/28 355/Super T-10 (Pat's toy) 93 Caprice 9C1 (Brian's Cop Car) 02 Toyota Camry (Reliable but a souless steel and plastic hulk) 2011 2SS RS Camaro M6 Factory Hurst Shifter Maybe I need to sell some of this crap Yet another Bozo with a sawz-all

03-02-2005, 12:33 PM	#2
BLAZERMAN Currently Blazerless Join Date: Apr 2000 Location: St. Joseph Mo. Posts: 4,826	I allways start with the yoke at the transfer case first and use a prybar or large screwdriver through the front yoke to turn and hold the shaft in place. If your lucky you will have the 7/16" head bolts at the TC , just use the shortest wrench you have, if your exhuast is run through the crossmember it can get real tight. If you do have the 7/16" bolts you can use a ratcheting wrench but if you have the 1/2" head there wont be enough room. __________________ 1972 C/30 133" W.B. C&C 1970 GMC 3500 157" W.B. single wheel C&C Last edited by BLAZERMAN; 03-02-2005 at 12:47 PM.

03-02-2005, 07:36 PM	#3
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	It's a pain even on lifted vehicles. My front output seal is leaking and in my situation I'm going to remove the crossmember. If you can remove the hump that would make it easier. __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

03-02-2005, 08:07 PM	#4
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,568	Did mine recently on my back in the carport. Unbolted the front crossmember & moved it out of the way (only way I could get to the nuts at the TC end of the shaft). Then I just unbolted the rear of the shaft, then the front. Bit of a PITA, it just went slowly due to limited access. __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay

03-02-2005, 09:59 PM	#5
jeffspower Well, Whoop-dee-do! Join Date: Mar 2003 Location: Easton, Mo. pop.- me & scarcely a few others Posts: 2,302	Come on, guys. Not to brag, but it isn't that tough as long as the bolt heads are not chewed up from the last guy. If the bolt heads are buried in guuk, take a right angle pick & dig them out before you round them off. I use the lockouts to position it where I want it, and wrench the two bolts at the top. It takes a little arm twisting and dexterity. Once you get them broke loose with a long wrench, you can work them out quick with a stubby wrench. Reach over & spin a lockout to position it to get the other two bolts. Once you get the hang of it, you can R&R one in about 1/2 an hour. __________________ '68 GMC shortbox 4x4 350/SM465/T221- bought it in '83 SOLD '72 K20 500 Cad/TH400/NP205 SOLD '92 Chevy 2500 6.5 mech TD 4L80E crusty daily driver '72 Monte Carlo... sweet low mile toy '11 Dodge Challenger IE 392 6spd... midlife car

03-03-2005, 09:58 AM	#6
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,568	Well, mine had never been touched, so nothing was chewed up from the last guy. And I did not round anything off. But I could not see any way at all to reach anything with the crossmember in place, so I moved it (which is not difficult). For me, the easy access made it worthwhile. YMMV __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay

03-04-2005, 05:00 AM	#7
4x4Poet Registered User Join Date: Nov 2004 Location: "Under Montana skies." Posts: 1,836	Jeffspower's advice is spot on. What makes it easier than it looks is the bolts screw into the yoke that takes the CV joint cross. They're little and fairly short. Initial bolt head cleanliness will greatly ease the task. IIRC, I used an offset box-end wrench in the backward position to make the handle angle away from the xfer case. __________________ '71 GMC K20 Suburban, '71 GMC K10 Suburban, '72 Chevy C10 CST Suburban, '72 Chevy K20 clunker pickup.



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